Recent Press Releases
The magnificent but mysterious snowflake
IOP
PW
Wed, 2 January 2008
The beautiful snowflake is much more than an attractive seasonal occurrence. In fact, understanding how a snowflake grows is a complex problem of molecular dynamics, writes Kenneth Libbrecht, Professor of Physics at the California Institute of Technology, in January’s Physics World.
Everyone knows that no two snowflakes are identical to one another. That's because they all start out as a simple hexagonal prism - the most basic form of snow crystal - but then encounter a range of atmospheric conditions as they journey down to Earth.
It was two Japanese physicists who made early strides in our understanding of snowflake formation. Ukichiro Nakaya at the University of Hokkaido in the 1930s and Takehiko Gonda in the 1970s at the Science University of Tokyo found that humidity, temperature, air pressure and other conditions are the variables that determine the shape of a snowflake.
Kenneth Libbrecht writes, “Although no two crystals end up exactly alike, the six arms of a single crystal all travel together, so they all grow in synchrony, giving each falling crystal a unique and intricate structure with a recognisable symmetry.”
The conditions in the atmosphere dictate how water molecules are transported to the crystal but, because of the wide range of conditions, that makes it hard to simulate snowflake growth and explain how particular structures are formed.
Numerical modelling is now being used to reproduce the complex structures. The work is of particular interest to metallurgists as a better understanding of snowflake structures could profoundly affect the strength and ductility of their own final materials on a micro- or even nano-scale.
Libbrecht continues, “Beyond the intrinsic scientific questions, beyond the practical applications of crystal growth, and beyond the meteorological significance of atmospheric ice, we who ponder snowflakes are motivated by a simple and essential desire to comprehend the natural world around us.”
Also in this issue:
- Funding bombshell hits UK physics
- The physics of dance
ENDS
PLEASE MENTION PHYSICS WORLD AS THE SOURCE OF THESE ITEMS AND, IF PUBLISHING ONLINE, PLEASE CARRY A HYPERLINK TO:
http://www.physicsworld.com
Notes to editors:
1. Physics World is the international monthly magazine published by the Institute of Physics. For further information or details of its editorial programme please contact the editor, Dr Matin Durrani on +44(0)117 930 1007. The magazine's Website physicsworld.com is updated regularly and contains physics news, jobs and resources. Visit http://www.physicsworld.com
2. For copies of Physics World and advance copies of the articles reviewed here contact: Joe Winters, press officer, The Institute of Physics, Tel: +44 (0)20 7470 4815 or +44 (0)7946 321473, email: joseph.winters@iop.org
3. The Institute of Physics is a scientific membership organisation devoted to increasing the understanding and application of physics. It has an extensive worldwide membership (currently around 34 000) and is a leading communicator of physics with all audiences from specialists through government to the general public. Its publishing company, IOP Publishing, is a world leader in scientific publishing and the electronic dissemination of physics.
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